Seismic soil pressures on underground metro station in soft soil: Experimental studies and analytical comparisons

The seismic design of metro stations relies on the accurate assessment of the magnitude and distribution of seismic soil pressures. Seismic soil pressure (SSP) is an important load acting on the side walls of metro stations and its magnitude and distribution shape have been one of the hot topics of research in the field of seismic resistance. In view of this, a shaking table test on a soil-metro station model under different seismic excitations was carried out, where SSP data were collected from the side walls and a residual was introduced to quantify the deviation of the test values from the analytical values. The results show that: (i) the difference between the absolute values of the SSPs along the left and right side walls at same burial depth and time is small, with one tension and one compression. (ii) The time history of the SSP along the side walls has periodic characteristics and first-order predominant frequency of SSP is consistent with that of the ground. (iii) The widely used analytical equations do not reflect the actual situation of the SSP along the side walls of the metro stations.